That's a fun idea, but the costs may turn you off to it. The main issue I see is the Zone you live in. First, you would need to build a greenhouse that has twinwall or triple wall glazing, second, it would have to be fairly large to have that kind of vegetable production, and third, due to the climate, your heating bill could be very large -- especially with world energy prices skyrocketing -- and could well exceed what it would cost to simply buy the vegetables. I did a simple calculation of what it would cost to heat a traditional 10' X 20' greenhouse with twinwall glazing to 65F in your Zone in the winter, and the cost came out to be about $1-$2 per hour. If you went with crops that didn't require as much heat (i.e., forget tomatoes, etc.) you could keep the greenhouse at a cooler temperature.

I'm not trying to discourage you, but I'd hate to see you spend a lot of money and end up disappointed due to unrealistic expectations. The best advice I can offer you is to research greenhouse design and consider building something that is attached to and integral with one wall of the house. There are certain ways to build so that you can maximize insulation and solar gain this way. For background and to get a good general idea of what your options are, you could start with "The Complete Book of the Greenhouse," by Walls. Good luck.

Here is a link that might be useful: Greenhouse calculator

If you're well-capitalized, the link below is to an article about a guy who has done what you suggest in a cool climate.

-Bruce C.

Here is a link that might be useful: Joseph Orr's solar greenhouse

It's not difficult but there's a learning curve. I fed my family of three and sold fresh greens in a 22 x 48 greenhouse all of last winter. You don't have to heat the greenhouse - you're better off if you don't. You need to learn what will grow and can be harvested in an unheated greenhouse. I bounce between zones 4 and 5. The greenhouse will add another half zone to bump you up to 6a. A layer of heavy duty row cover on hoops will bump you up to 6b.

Don't try to grow tomatoes, peppers and other warm season crops in an unheated greenhouse in winter. You'll need to grow cold weather greens and root crops. Growth stops here around mid December and doesn't start again til about the end of the first week in February when the sun has gotten a little higher. During the time greens and roots aren't growing you can harvest fresh vegetables.

You'll need to get your plants and seeds in with plenty of time for them to get established before they stop growing. The closer you get to December the slower the plants are going to grow. I'll transplant seedlings in September and October. Seeds will go in sometime in late August as space allows.

Carrots, beets and turnip can be harvested in the winter. Tatsoi, bok choi, beet greens, cold weather lettuces and spinach are easy to grow in an unheated greenhouse. Eliot Coleman's book Four Season Harvest is essential. I'll link to it below. While you're on that website, take a look at the photo gallery!

Winter Harvest Manual

Four Season Harvest

Good luck!

This is a gross generalization, but to build a 'proper' greenhouse is going to be in the $3000+ range, to purchase a kit and do the opther work. Remember, you'll need electrical and foundation work even before the actual build. You'll need a heater and fan (or multiples), unless you're going to try to manually regulate the temps in there by continually opening/closing openings. I would love a nice greenhouse --- just way to expensive for me. I'm sure you've looked at online sites that show you some of the prices.
Here are some kit examples (again, remember, this is simply a kit with no foundation or electrical components).
http://www.greenhouses.com/value-greenhouses.html

consider a pit greenhouse. Scroll down a little on this link.
~tom

Here is a link that might be useful: Solar pit Greenhouse

how about the attached type sun space type greenhouses?

sorry if i'm piggybacking on this thread (maybe my Q's will help Ben as well), but i have been searching for info all over the place for plans and ideas.

i'm thinking a lean-to type might work better for me, attached to the house with access through what used to be an exterior wall by new sliding glass doors. Also having a second door for access to outside... i am not planning on tromping seed flats through the house en route to the garden in the back, lol.

i have questions about heating it also, if the wide side faces south, the ends facing east/west, (with no architectural obstructions) will it potentially get plenty of light and heat year round for houseplants, perhaps tropicals? will it absorb some energy to add some heat to the house during the day- enough to offset the strain of sending back warmth to the greenhouse at night? if not, is there an easy way to insulate the exposed glass at night- some sort of roll-down shade system, similar to insulated roman shades in a regular window?

My main interests/needs for a green structure of some sort is:

1. early start for veggie garden seeds and annual starts
2. year round places to keep my floundering citrus and tropicals who aren't getting enough light in even my best windows
3. a nice place to sit and enjoy

any build plan info, trouble shooting, economy hints, personal experience and or regrets etc are appreciated.

I too am a beginner. I built my self, on the south side of our garage. The south wall of our garage is the n wall of the greenhouse. It has power to it also. My biggest problem is trying to find seeds... It seems like in my area I can only get seeds in May, early June.

I recommend builing yourself. Dont let the commercialism of our world tell you you have to spend a fourtune on this endeaver. I spent less than 100 dollars for the structure and plants/seeds. Call me cheap or frugal but our family of 5 is eating beautiful veggies already!

Other good questions: Costs to run power, books/literature on what to grow when, and how to store vegetables once picked. I realized gardening for years taught me nothing once I had the harvest I do now... What do I do with all the left overs? LOL

Icebear -- in your USDA Zone, you may want to consider orienting your gh (if possible, I understand your limitations if you attach to your house) so that the long wall dimension faces east, and completely walling off/insulating the north wall. If your plans are to winter-over sensitive plants, or start plants early, you're going to be heating. The worst of your temperatures are going to be at night/early morning. With the long wall facing east, you will benefit from that morning sun which will quickly move your interior temps higher. During that time in the morning (if you select your site properly), the sun's rays will be low, which will shine right through that wall.

In contrast, later on in the day, much of your light will come through the roof, except for those plants along the south wall. As a matter of fact, it may be necessary to add shade cloth along the south side because the light may be too intense.

Place your door on the west or north side, to avoid the additional framing from cutting down on your light.

I grow orchids, and have a light structure with a relatively poor R-value. The orientation I described above is the only reason I can grow orchids in this climate (winter temps to 20F) with a minimal heating expense.

-Bruce C.

Hi !, I am also a beginner as well and also need help.I live in south eastern Massachusetts and plan on building a hoop style greenhouse..10ft.wide, 16ft. long and 7 ft. high, double poly. I want to grow tropicals such as palms,banana, philodendron, and orchids.I have no clue as to how I am going to heat the thing! Money is very tight right now. Winter temps.average in the low 20`s and lower at times.Do I go with an electric hearer? What about trying to find a smaller pellit stove? Would it help if I were to put down interlocking black rubber foam flooring, the kind used in gyms as a way to help heating? As you all can see, I really do need some help.

Hello, could anyone help me Please? I have recently bought a 6x4 green house. The area i am putting it on is slightly sloped and I need to make this level. I have so paving slab.. how am I best to go about this?